Black Box Testing

What is Black Box Testing?

In Black Box Testing, the tester tests an application without knowledge of the internal workings of the application being tested. Data are entered into the application and the outcome is compared with the expected results; what the program does with the input data or how the program arrives at the output data is not a concern for the tester performing black box testing. All that is tested is the behavior of the functions being tested.

This is why black box testing is also known as functional testing which tests the functionality of a program. Note we can also have non-functional black box testing, such as performance testing which is a type of black box testing but instead of verifying the behavior of the system, it tests how long it takes for a function to respond to user’s inputs and how long it takes to process the data and generate outputs.

Because black box testing is not concerned with the underlying code, then the techniques can be derived from the requirement documents or design specifications and hence testing can start as soon as the requirements are written.